Last I heard Ben has the trailer and as I understand it what you "donate" to the trailer becomes the parts available to anyone at CM that may need them. I've never actually looked in the trailer though to see what is in there, just how I understand it works from what Ben explained to me when I donated some parts for CM07.

An important thing to keep in mind, and what Ben explained to me when I asked him whether what I was donating was "ok", is that the part doesn't have to perfect, just good enough to get someone off the trail